Hacking hashes

#include <iostream>
#include <vector>
#include <unordered_map>
#include <string>
#include <cstdlib>

int A, B;

int F(const std::vector<char>& s) {
    int h = 0;
    for (char c : s) {
        h = (h * A + static_cast<int>(c)) % B;
    }
    return h;
}

void sortie(const std::string& string_1, const std::string& string_2) {
    std::cout << string_1 << ' ' << string_2;
    std::exit(0);
}

int main() {
    std::cin >> A >> B;

    std::vector<char> alphabet;
    for (char c = 'a'; c <= 'z'; ++c) {
        alphabet.push_back(c);
    }

    int size = 0;
    std::unordered_map<int, std::string> verif;

    while (true) {
        ++size;
        std::vector<int> calc(size, 0);
        std::vector<char> string(size, 'a');
        int i = size - 1;

        while (i >= 0) {
            if (i == size - 1) {
                for (char ch : alphabet) {
                    string[i] = ch;
                    int res = F(string);
                    auto it = verif.find(res);
                    if (it != verif.end()) {
                        std::string str_2(string.begin(), string.end());
                        if (str_2 != it->second) {
                            sortie(str_2, it->second);
                        }
                    } else {
                        verif[res] = std::string(string.begin(), string.end());
                    }
                }
                --i;
            } else {
                if (calc[i] == static_cast<int>(alphabet.size()) - 1) {
                    --i;
                } else {
                    ++calc[i];
                    string[i] = alphabet[calc[i]];
                    ++i;
                }
            }
        }
    }

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: WRONG ANSWER

Test 55

Verdict: WRONG ANSWER

Test 56

Verdict: WRONG ANSWER

Test 57

Verdict: WRONG ANSWER

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: WRONG ANSWER

Test 60

Verdict: WRONG ANSWER

Test 61

Verdict: WRONG ANSWER

Test 62

Verdict: WRONG ANSWER

Test 63

Verdict: WRONG ANSWER

Test 64

Verdict: WRONG ANSWER

Test 65

Verdict: WRONG ANSWER

Test 66

Verdict: WRONG ANSWER

Test 67

Verdict: WRONG ANSWER

Test 68

Verdict: WRONG ANSWER

Test 69

Verdict: WRONG ANSWER

Test 70

Verdict: WRONG ANSWER

Test 71

Verdict: WRONG ANSWER

Test 72

Verdict: WRONG ANSWER

Test 73

Verdict: WRONG ANSWER

Test 74

Verdict: WRONG ANSWER

Test 75

Verdict: WRONG ANSWER

Test 76

Verdict: WRONG ANSWER

Test 77

Verdict: WRONG ANSWER

Test 78

Verdict: WRONG ANSWER

Test 79

Verdict: WRONG ANSWER

Test 80

Verdict: WRONG ANSWER

Test 81

Verdict: TIME LIMIT EXCEEDED

Test 82

Verdict: WRONG ANSWER

Test 83

Verdict: WRONG ANSWER

Test 84

Verdict: WRONG ANSWER

Test 85

Verdict: TIME LIMIT EXCEEDED

Test 86

Verdict: TIME LIMIT EXCEEDED

Test 87

Verdict: WRONG ANSWER

Test 88

Verdict: WRONG ANSWER

Test 89

Verdict: WRONG ANSWER

Test 90

Verdict: WRONG ANSWER